PROJECT SUMMARY/ABSTRACT Negative influence from peers and friends is a well-known potent predictor of adolescent smoking initiation. However, what is not known is how to design and implement an intervention that promotes positive social influence for adolescents (i.e., connection with and support from others who do not intent to smoke). One example of an intervention that lacks positive social influence is a Web-based, computer-tailored intervention called A Smoking Prevention Interactive Experience (ASPIRE; developed by primary mentor). ASPIRE includes a series of videos and activities with messages designed through the Trans-Theoretical Model of Change. ASPIRE successfully provides adolescents individually with information on smoking risks, using human-computer interaction. Still, for better outcomes, it can benefit from positive social influence through peer-to-peer interaction. The long-term research goal is to develop, implement, and evaluate social influence and behavioral interventions that can be applied to prevent the use of nicotine/tobacco products among adolescents. One innovative approach to fill the gap is to apply social influence strategies. First, game-based social activities (GSAs) can facilitate exploration of health information and drive social discussions against smoking. Second, social network analysis allows us to strategically group at-risk adolescents (i.e., those who intend to smoke), with close peers who do not intend to smoke (i.e., change agents), as they engage in ASPIRE. Change agents will positively influence at-risk adolescents for two reasons: (1) At-risk adolescents will be dominated in number by change agents, and (2) their interaction with change agents will be directed by the healthy content of ASPIRE and the GSAs. The objective of the current research is to identify the effect of ASPIRE on key mechanisms underlying adolescents? intention to smoke nicotine/tobacco products (cigarettes, cigars, hookah water pipes, and electronic cigarettes), when social influence strategies are added to the intervention. The central hypothesis is that the addition of social influence strategies to ASPIRE will boost ASPIRE?s success in lowering intention to smoke. This hypothesis has been formulated based on preliminary data with ASPIRE and theoretical frameworks indicating how GSAs and social grouping can be successful. The rationale is that new evidence will provide supportive data for the subsequent development and evaluation of a social influence intervention for smoking prevention at the R01 level. The long-term career goal is to become an independent researcher, expert in the design, implementation, and evaluation of interventions that apply (1) social influence, (2) entertainment, and (3) technology for the prevention of nicotine/tobacco use among adolescents. Along with mentorship, a comprehensive training plan is developed to tap on these 3 areas for the K99 phase, allowing a flawless transition to the R00 phase. Ultimately, the research and training plans have the potential to inform the development of an R01 project to design and evaluate a comprehensive intervention for adolescents, with positive social influence as a driver of smoking prevention.